fix(uv_venv): fixes PATH ordering with mise x

[jdx]

Fixes #5999

[Copilot]

Pull Request Overview

This PR fixes PATH ordering for UV virtual environments when using mise x command to ensure project virtual environments take precedence over tool paths. The fix addresses a specific issue where UV venv paths were being added after tool paths in the PATH order.

• Reorders PATH priority to place UV venv paths before tool_add_paths and tool paths
• Updates comments to reflect the new ordering logic
• Adds an end-to-end test to validate the fix

Reviewed Changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.

File	Description
src/toolset/mod.rs	Reorders PATH construction to prioritize UV venv paths over tool paths
e2e/core/test_python_uv_venv_x_tiny	Adds test case to verify UV venv precedence when using mise x

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[github-actions]

Hyperfine Performance

mise x -- echo

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
mise-2025.8.8 x -- echo	19.0 ± 0.7	18.0	22.4	1.00
mise x -- echo	19.1 ± 0.8	18.0	24.0	1.00 ± 0.06

mise env

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
mise-2025.8.8 env	18.3 ± 0.6	17.5	22.0	1.00
mise env	18.9 ± 0.8	17.4	24.0	1.03 ± 0.06

mise hook-env

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
mise-2025.8.8 hook-env	18.2 ± 0.7	17.1	20.5	1.00
mise hook-env	18.9 ± 0.8	17.1	21.0	1.04 ± 0.06

mise ls

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
mise-2025.8.8 ls	17.3 ± 0.6	16.1	19.2	1.04 ± 0.06
mise ls	16.7 ± 0.8	15.5	20.9	1.00

xtasks/test/perf

Command	mise-2025.8.8	mise	Variance
install (cached)	197ms	✅ 107ms	+84%
ls (cached)	84ms	✅ 64ms	+31%
bin-paths (cached)	68ms	69ms	-1%
task-ls (cached)	480ms	494ms	-2%

✅ Performance improvement: install cached is 84%
✅ Performance improvement: ls cached is 31%